Email validation is a crucial step in email marketing to prevent sending to bad email addresses, which can harm the deliverability of our email account and sending IPs.
However, with so many options available in the market, it can be hard to decide which one works best and provide the best accuracy per cost.
To answer that question and find the best value option out of so many competing providers that all claimed to be the best, I have decided to try out each of them and run a small benchmark.
Benchmark Methodology
The idea is simple. We took 50 emails from our recent campaign that we knew were valid, and then we added random characters to each email address to create 50 bad emails.
We then upload these 50 email addresses to those email list cleaning services to let them verify our email list and see which of them gives the best results.
Those 50 email addresses do not include an email from free email providers such as Gmail or Outlook. All of them are in the business domain, and none of them are generic / role-based.
However, since the sample size is so small, it shouldn’t be seen as a comprehensive benchmark but rather as a quick overview of how these services perform.
Update 23 Aug 2022: We added some tests on a few services, but this time instead of uploading bad email addresses, we uploaded 50 deliverable email addresses to see if they reported any false positives. Lots of false positive means leads are being wasted.
The Email Validation Results
Without further ado, let’s dive into the results and see which email verification service is the best value option!
1. ZeroBounce
Website: https://www.zerobounce.net/
Price Per Email: From $0.008
- Invalid (mailbox_not_found) – 41
- Catch-all – 9
2. NeverBounce
Website: https://neverbounce.com/
Price Per Email: From $0.008
- Invalid – 40
- Accept All (Unverifiable) – 10
3. EmailListValidation
Website: https://emaillistvalidation.com/
Price Per Email: From $0.0076
There’s an ongoing lifetime deal at $59 for 1 million credit while writing this, making it $0.000059 per email validated, and the credit renews every year.
- Deliverable – 2
- Invalid – 35
- email_disabled – 34
- antispam_system – 1
- Accept All (Catch-all)- 13
4. KleanMail
When I tested this, this seemed like a new, untested product with very bad results. The interface is buggy, and worse of all, it took more than half an hour to validate 50 email addresses.
Website: https://www.kleanmail.com/
Price Per Email: From $0.0055
While writing this, there is also an ongoing lifetime deal at $49 for 1 million credit, making it $0.000049 per email validated, but it is a one-time credit and doesn’t renew.
- Deliverable – 6
- Invalid (hard_bounce) – 31
- Error – 6 (SMTP Error – communication not established)
- Email not being validated – 7 (Somehow, it skipped these, probably another bug?)
5. ClearOut.io
Website: https://clearout.io/
Price Per Email: From $0.007
- Invalid (hard bounce) – 41
- Catch-all – 9
False positive test (With 50 known deliverable email addresses):
- Valid – 44
- Safe to send – 32
- Risky – 12
- Catch-all – 6
- Risky – 6
6. QuickEmailVerification.com
Website: https://quickemailverification.com/
Price Per Email: From $0.008
- Invalid (hard bounce) – 40
- Catch-all – 9
- Unknown – 1 (no connection)
7. Bouncer
Website: https://www.usebouncer.com/
Price Per Email: From $0.007
- Deliverable – 1
- Undeliverable (hard bounce) – 37
- Risky (catch-all) – 8
- Unknown – 4
8. EmailListVerify
Website: https://www.emaillistverify.com/
Price Per Email: From $0.004
- Deliverable – 1
- Undeliverable (email_disabled) – 41
- Risky (catch-all) – 8
9. Emailable
Website: https://emailable.com/
Price Per Email: From $0.006
- Undeliverable (Rejected) – 42
- Risky (catch-all) – 8
False positive test (With 50 known deliverable email addresses):
- Deliverable – 41
- Risky – 9
10. Kickbox
Website: https://kickbox.com/
Price Per Email: From $0.01
- Undeliverable (rejected_email) – 32
- Risky (catch-all) – 16
- Unknown – 2
11. Mailcheck.co
Website: https://mailcheck.co/
Price Per Email: From $0.01
I decided to test this because they are running a lifetime deal at appsumo for $59 and you get 100k credits per month. But I did not get it because their false positives are high!
- Invalid (10) – 46
- Risky (50) – 4
False positive test (With 50 known deliverable email addresses):
- Invalid (10) – 22
- Invalid (40) – 1
- Invalid (50) – 4
- Valid (90-100) – 23
What’s the verdict?
From the test, we’ve seen some close results of certain providers, and we suspect a few might be just resellers providing services via the API of another service.
It also shows that price does not directly correlate to effectiveness, for example Kickbox lowest purchase start at 500 credits, at $0.01 per email validated. It is the most expensive of all tested, yet the results aren’t satisfying either.
Our ranking based on cost-effectiveness
- Emailable – $0.006/email
- Clearout.io – $0.007/email
- ZeroBounce – $0.008/email
If you absolutely want the cheapest option, you can probably use a combination of two email list cleaners, for example, use the lifetime deal of EmailListValidation to clean your email once, discard the invalids then clean it again with Emailable.
However, using a combination to clean your list in the above way also means if there are false positives in some of the email addresses discarded by the first email cleaner, it would be wasted leads.
Run your own test
This benchmark are meant to give an overview, but the results may vary, this is because we only tested with 50 email addresses, and that is very small sample size to have any definitive conclusion on.
You can improve the test a few ways:
- Test with more email addresses
- Test with known valid email addresses too, to see if any services wrongly discard valid email
- Test more providers
We only run this test in such small sample size because we only use the free credits offered by these providers to conduct the test, but if you are a heavy user it is worth investing some to test at a larger sample size.
Hopefully, this post will be helpful for you while choosing an email list validation provider.
If we missed out on anything or you would like us to compare more providers, feel free to leave a comment below. (we read every comment!)